The proposed study is designed to further characterize the reproductive hazards that confront females engaged in occupations which subject them to potential exposure to pesticides. One segment of this study will be directed toward assessing whether the previously observed ovarian toxicity of Kepone in the adult female mouse has its basis in alterations either in ovarian steroid hormones or in the cell membranes of the different cellular components of the ovary. Ethylene dibromide (EDB), a pesticide that has attracted much attention recently because of its role in the fumigation of fruits, but, heretofore, not examined critically for its effect on the female reproductive system, will also be assessed. Virgin female mice (7-10 weeks old) will be subjected to acute pesticide exposure (5 consecutive days) or longer term exposure (5 consecutive days for four consecutive weeks). Hormones to be monitored include estrogen and progesterone. Hormonal blood levels will be correlated with cell surface characteristics of granulosa cells, luteal cells and the oocyte. Alterations in cell surface characteristics will be detected by employing lectin conjugated probes to detect specific binding sites of different carbohydrates within the cell membranes. These data will provide evidence as to whether these pesticides induce cell surface alterations and, thus, affect binding sites for different hormones. The second part of this study will ascertain whether there is a period(s) during embryonic development when the ovaries are most sensitive to Kepone so as to specify the embryonic process altered accounting for the reproductive toxicity induced by prenatal exposure to Kepone. Pregnant mice will be exposed to Kepone for different time intervals during gestation. Female offspring will be sacrificed at birth, at weaning and at two months of age. Parameters to be assessed at all three times will be ovarian, brain and liver weights and a tabulation of the types of ovarian follicles present. Pregnant females exposed to Kepone during pregnancy will also be examined after they deliver to evaluate their future reproductive activity. The information gained from this study will further our understanding of how a pesticide works. In addition, it will assist in establishing critical guidelines that both employer and female employee can utilize in making judgments regarding the present or proposed occupation.